000
AXPZ20 KNHC 160951
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI MAY 16 2008

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN
FROM THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0945 UTC.

...ITCZ...

ITCZ AXIS IS ALONG 08N78W TO 04N85W TO 08N95W TO 10N120W TO 
04N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED 
WITHIN 240 NM EITHER SIDE OF LINE FROM 06N77W TO 12N103W TO 
07N113W TO 08N126W.

...DISCUSSION...

AN UPPER LEVEL CYCLONE IS CENTERED AT 22N138W WITH ITS ENVELOPE 
OF CYCLONIC FLOW DOMINATING THE DISCUSSION AREA FROM 10N TO 28N 
W OF 130W. AN UPPER LONGWAVE TROUGH DISSECTS N AMERICA FROM NE 
TO SW AND ENTERS THE AREA THROUGH A SMALL UPPER CYCLONE AT 
32N109W.
THE UPPER TROUGH THEN BECOMES SLIGHTLY NEGATIVE TILT AND 
CONTINUES S TO A BASE NEAR 16N108W. A BAND OF DRY UPPER AIR IS 
NOTED WITHIN THE TROUGH...ROUGHLY WITHIN 180 NM EITHER SIDE OF 
LINE 21N106W TO 32N124W.

AN UPPER ANTICYCLONE IS OBSERVED NEAR 13N115W WITH A NARROW 
UPPER RIDGE EXTENDING N TO A CREST AT 25N125W AND EFFECTIVELY 
SEPARATES THE UPPER CYCLONES. UPPER DIFFLUENCE ENHANCED ITCZ 
CONVECTION BETWEEN 110W AND 140W AND THE DEBRIS MOISTURE IS 
SPREADING FROM 5N TO 25N BETWEEN 122W AND 133W. 
 
FURTHER E...AN UPPER RIDGE EXTENDS ALONG 09N78W TO NEAR 17N102W.
CONVECTION ALONG THE ITCZ E OF 110W IS ENHANCED AND THE 
RESULTANT DEBRIS MOISTURE IS ADVECTED N ACROSS CENTRAL AMERICA 
BUT APPEARS TO EVAPORATE IN VERY DRY AIR ALOFT OVER THE W 
CARIBBEAN.

$$
NELSON